This invention relates generally to continuous positive airway pressure ventilation systems such as respirators and in particular to a new and useful non-invasive adaptive controller of blood system oxygen. The system has particular application in the adaptive control of neonatal fractional inspired oxygen (FiO.sub.2) and is intended to make more automatic the control of oxygen to the patient whether the patient be neonatal or mature.
This system utilizes a pulse oximeter to optically determine hemoglobin saturation of the patient's blood and use this information to regulate oxygen delivered to the patient's breathing mask or hood. The control mechanism is derived from the known relationship between the minimum required FiO.sub.2 delivered to the patient and predetermined lung function dynamics in order to maintain a desirable arterial blood hemoglobin saturation level (HSAT).
The use of a pulse oximeter permits non-invasive determination of a patients arterial blood hemoglobin saturation and pulse rate. From the measured hemoglobin saturation and pulse rate a non-invasive determination of pulse rate and blood pressure parameters can be used to determine patient movement and apnea to suspend and correct, respectively, the operation of the system without requiring operator intervention.